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From John Lilley <john.lil...@redpoint.net>
Subject RE: Shuffle phase replication factor
Date Wed, 22 May 2013 14:33:51 GMT
Oh I see.  Does this mean there is another service and TCP listen port for this purpose?
Thanks for your indulgence... I would really like to read more about this without bothering
the group but not sure where to start to learn these internals other than the code.

From: Kai Voigt [mailto:k@123.org]
Sent: Tuesday, May 21, 2013 12:59 PM
To: user@hadoop.apache.org
Subject: Re: Shuffle phase replication factor

The map output doesn't get written to HDFS. The map task writes its output to its local disk,
the reduce tasks will pull the data through HTTP for further processing.

Am 21.05.2013 um 19:57 schrieb John Lilley <john.lilley@redpoint.net<mailto:john.lilley@redpoint.net>>:

When MapReduce enters "shuffle" to partition the tuples, I am assuming that it writes intermediate
data to HDFS.  What replication factor is used for those temporary files?

Kai Voigt

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